System and method for additive metal manufacturing

ABSTRACT

A system for additive metal manufacturing, including a deposition mechanism, a translation mechanism mounting the deposition mechanism to the working volume, and a stage. A method for additive metal manufacturing including: selectively depositing a material carrier within the working volume; removing an additive from the material carrier; and treating the resultant material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/851,028 filed 28 Jun. 2022, which is a divisional of U.S. applicationSer. No. 16/744,657 filed 16 Jan. 2020, which is a continuation of U.S.application Ser. No. 16/102,422 filed 13 Aug. 2018, which is acontinuation of U.S. application Ser. No. 15/705,548 filed 15 Sep. 2017,which claims the benefit of U.S. Provisional Application No. 62/395,289filed 15 Sep. 2016 and U.S. Provisional Application No. 62/407,318 filed12 Oct. 2016, all of which are incorporated in their entireties by thisreference. This application is related to U.S. application Ser. No.15/594,472 filed 12 May 2017, which claims the benefit of U.S.Provisional Application No. 62/335,679 filed 13 May 2016 and U.S.Provisional Application No. 62/421,707 filed 14 Nov. 2016, all of whichare incorporated in their entireties by this reference.

TECHNICAL FIELD

This invention relates generally to the additive manufacturing field,and more specifically to a new and useful metal manufacturing system andmethod in the additive manufacturing field.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of a variation of the system.

FIG. 2 is a schematic representation of an example of the system.

FIGS. 3A, 3B, and 4 are examples of vacuum shrouds that can be used.

FIGS. 5 and 6 are examples of the relationship between the stagetranslation axes and mechanism translation axes.

FIG. 7 is an example of a workpiece retention mechanism.

FIG. 8 is a schematic representation of an example of treatment volumearrangement relative to the working volume.

FIG. 9 is a schematic representation of an example of transferring theworkpiece from the working volume to the treatment volume.

FIG. 10 is a flowchart representation of the method.

FIGS. 11, 12, and 13 are flowchart representations of a first, second,and third variation of the method, respectively.

FIGS. 14, 15, and 16 are schematic representations of a first, second,and third specific example of the method, respectively.

FIGS. 17 and 18 are a first and second example of the system,respectively.

FIG. 19 is an example of the deposition head and manipulation headarrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

1. Overview

As shown in FIG. 1 , the system for additive metal manufacturingincludes: a deposition mechanism, a translation mechanism mounting thedeposition mechanism, and a stage. The system can optionally include amaterial manipulation mechanism, an additive removal mechanism, asintering mechanism, a treatment mechanism, sensors, a stage, a workingvolume, a control system, and/or a power system.

As shown in FIG. 10 , the method for additive metal manufacturingincludes: selectively depositing a material carrier in a predeterminedlocation within the working volume; removing an additive from thematerial carrier; and treating the resultant material. The method canoptionally include manipulating the material; and monitoring theadditive manufacturing process and dynamically adjusting the additivemanufacturing parameters based on process monitoring.

The system and/or method function to enable metal piece manufacturethrough layerwise material processing.

2. Benefits

The system and/or method can confer several benefits over conventionalsystems.

First, in some variants, the method can reduce overall part distortionby removing additives from the material carrier between depositionsteps. For example, in variants where the material carrier (e.g., buildmaterial) includes a metal paste, the method can remove the solvent fromthe paste layers after a predetermined number of paste layers have beendeposited (e.g., after each layer 10 has been deposited). This canfurther decrease the overall part manufacturing time, since solvent canbe removed from a thin layer of paste faster than it can be removed fromthe entirety of a wet workpiece. In another example, variants of themethod can use material carriers that do not require debinding (e.g., abinderless build material), which can decrease the geometry changebetween initial printing and the final part.

Second, in some variants, the method can improve part resolution and/orsurface finish by leveraging a hybrid manufacturing technique. Thehybrid manufacturing technique can include manipulating (e.g.,machining, forming, etc.) the material carrier, a part precursor (e.g.,green body or brown part), and/or the material before the piece isfinalized (e.g., before the final geometry is formed, before the pieceis treated, etc.). For example, each material layer 10 can be machinedafter it is deposited. Manipulating the material prior to treatment canfunction to reduce the amount of manipulation force required to create adesired geometry, to control inter-layer interfaces (e.g., level thelayer 10 before subsequent layer deposition), to shape surfaces that areenclosed or rendered inaccessible by subsequent layers (e.g., finishinterior surfaces), or confer any other suitable set of benefits.

Third, some variants of the method can achieve improved part resolutionand/or surface finish by creating a green body with near-net geometry(e.g., a near-net part precursor), then controlling or minimizing thegeometry change during green body processing into the end product. Forexample, method variants can create near-net part precursors using abuild material that has less than a threshold shrinkage between thegreen body and the final part (e.g., less than 30%, 20%, 10%, 5%, 8-12%,or any other suitable percentage volumetric or linear dimensional changewith 1%, 0.1%, 0.01%, or any other suitable precision), by using hybridmanufacturing techniques, by using a combination of the above, orotherwise creating the near-net part precursor. In a specific example,the method can use a binderless paste (e.g., a paste with less than athreshold percentage of binder, paste with no binders) as the buildmaterial, or use a paste with additives that can be removed (e.g.,evaporated, burned off) between deposition steps.

Fourth, the inventors have discovered that conventional coolingtechniques for machined parts (e.g., spraying coolant onto theworkpiece) can result in undesirable part deformation in some variantsof the method, such as when the layers form soft solids are used inhybrid manufacturing systems. Soft solids can be soft solids deformableparts, parts with low rigidity, or otherwise defined. In these variants,the inventors have discovered that not cooling the machining tool, orusing less forceful cooling techniques (e.g., convection, conduction,etc.), can provide sufficient cooling. In other variants, the inventorshave discovered that it can be desirable to maintain the temperature ofthe: printed layer, machine tool, local build volume (e.g., local thelayer, local the machined layer portion), entire build volume, or otherregion at the uncooled tool operating temperature. This variant canresult in tighter tolerances, since all components (e.g., the workpieceand the tool) are maximally thermally expanded at the uncooled tooloperating temperature throughout the deposition and manipulationprocesses (e.g., the components do not breathe throughout theprocesses). In this variant, the waste heat from the layer machining canoptionally be recycled to passively heat the local build volume andremove the build material additive and/or cure the build material layer,or otherwise used.

Fifth, the inventors have discovered that conventional fixturingtechniques for machining, such as soft jaw fixturing, can be difficultto use or result in undesirable part deformation when soft solids areprocessed using hybrid manufacturing systems. The inventors have furtherdiscovered that fixing the part precursor to the build plate usingadhesives, magnetic attraction, a combination of the above, and/or otherretention mechanisms can individually or cooperatively providesufficient retention forces during machining to resist or overcome theshear forces applied by the machining tool to the part precursor duringmaterial manipulation.

3. System

As shown in FIG. 1 , the system 100 for additive metal manufacturingincludes: a deposition mechanism 200, a translation mechanism 300mounting the deposition mechanism 200 to the working volume 140, and astage 500. The system 100 can optionally include a workpiece retentionmechanism 510, an additive removal mechanism 400, a materialmanipulation mechanism 600, a treatment mechanism 800, sensors 120, acontrol system 160, and/or a power system. The system 100 functions toprint metal layers within the working volume, print support layerswithin the working volume, remove additives from the material carrier,treat the resultant part precursor, and/or perform any other suitablefunctionality.

A variation of the system 100 includes a working volume; a translationmechanism arranged within the working volume 140 and actuatably mountinga deposition mechanism (e.g., extrusion head), a material manipulationmechanism (e.g., a machining cutting tool), and an additive removalmechanism operable between a drying mode and a sintering mode (e.g., aheating element with an environment control mechanism); a stage opposingthe translation mechanism 300 in the working volume; a control system160 controlling translation mechanism, deposition mechanism, materialmanipulation, and additive removal mechanism operation; and an annealingmechanism separate from and fluidly connected to the working volume. Thedeposition mechanism, a material manipulation mechanism, and an additiveremoval mechanism preferably have a fixed relative position along afirst and second axis (e.g., x and y axes), and actuate relative to eachother along a third axis (e.g., z axis), but can be otherwisepositionally related.

All or a subset of the system components can be removably coupled to thesystem housing, which can confer system flexibility andreconfigurability. The system components can be removable, hot-swappable(e.g., replaceable during system operation), or otherwise coupled to thesystem 100. The system components can be manually replaced,automatically replaced (e.g., by a replacement system including anactuator and a set of sensors 120 configured to monitor consumablecomponent wear, position, etc.), or otherwise replaced. In onevariation, the deposition mechanism 200 (or a component thereof, such asthe material storage) can be replaceable during system operation,wherein the system 100 can automatically connect a new materialcartridge to the deposition head 210 in response to the fill level in apreceding cartridge falling below a threshold level. In a secondvariation, the tool holder can automatically release and pick up a newtool (e.g., from a tool repository mounted to the working volume).However, consumable system components (e.g., deposition mechanisms,additive removal systems, etc.) or any other suitable component can bestatically mounted to the system 100 or otherwise coupled to the system100.

The system 100 preferably deposits material layers between 5 μm and 250μm thick, but can alternatively deposit layers having any other suitablethickness. The system 100 preferably deposits material lines that arebetween 50-500 μm wide, but can alternatively deposit material linesbetween 0.5-5 mm wide or having any other suitable width. The materialdeposition speed is preferably between 10-500 mm/s, but canalternatively be slower or faster. The system 100 is preferably capableof building geometries with overhangs and other complex geometries forsmall feature sizes (e.g., less than 500 μm, less than 200 μm, etc.),but can alternatively be capable of building geometries having any othersuitable parameter values. The system 100 preferably has a positionalresolution on the order of 100 μm, but can alternatively have higher orlower positional resolution.

The system 100 preferably deposits (e.g., prints) and manipulates aworking material, which forms the final part geometry. The workingmaterial can be metal, ceramic, or be any other suitable material. Themetal can include iron (e.g., be ferrous), steel, aluminum, nickel,titanium, or any other suitable metal. In one variation, the workingmaterial can include a scaffold material and an infiltrant material(e.g., form a self-infiltrated material). The working material caninclude nanoparticles, microparticles, chips, or have any other suitablesize. The working material is preferably deposited as part of a workingmaterial carrier, but can alternatively be deposited as one of a set ofdeposition reagents (e.g., a carrier and curing agent pair), bedeposited as a powder, or be deposited in any other suitable formfactor.

The working material carrier 12 (build material) preferably includes theworking material and one or more additives that adjusts the physicalproperties (e.g., handling properties) of the working material, but caninclude any suitable material. The material carrier 12 preferablycreates a chipforming composite, but can alternatively form a compositewith any other suitable set of properties. The material carrier 12 ispreferably a paste (e.g., material particles suspended in a solvent,with or without binders), but can alternatively be a clay, metal matrixcomposite, metal foil, filament, an ink, aerosol, feedstock (e.g.,material particles with a binder, etc.), or have any other suitable formfactor. The paste can have a low viscosity that enables the depositedpaste layer to fill in cracks, pores, or other imperfections in thepreviously-deposited layer (e.g., prior layer, previous layer, precedinglayer, adjacent layer, etc.), or can have any other suitablecharacteristic. The binder can include one or more of a: polymer (e.g.,thermoset plastics, thermoplastic, epoxy, etc.), plastic, ceramic,liquid, wax, or be any other suitable binder. In one variation, thematerial carrier 12 can include one or more materials disclosed in U.S.application Ser. No. 15/594,472, incorporated herein in its entirety bythis reference. In a second variation, the material carrier 12 caninclude a binderless paste that includes material particles suspended ina solvent, without a polymer binder or with less than a thresholdpercentage of binder by weight, mass, or volume (e.g., less than 50%,25%, 10%, or other percentage by volume; less than 8% 3%, 1%, or otherpercentage by mass, etc.). The solvent can be volatile within theworking temperature range (e.g., have a boiling or sublimation pointless than or equal to a temperature within the working temperaturerange; example shown in FIG. 14 ) or liquid at the working temperaturerange (e.g., wherein the deposited layer 10 can be subsequently heatedor otherwise treated to remove the solvent). The solvent can be organic,inorganic, or have any other suitable property. Examples of the solventinclude water, ethanol, propane, butane, acetone, propanol, hexanal,formaldehyde, plasticizers, or any other suitable solvent.

The system 100 can additionally deposit and manipulate a supportmaterial 16, which functions to support the working material during partmanufacture (e.g., during part printing). The support material 16 canhave a lower melting point or decomposition point than the workingmaterial, be more volatile than the working material, be more brittlethan the working material, or have any other suitable physicalproperties relative to the working material. The support material 16 caninclude carbonaceous microparticles (e.g., graphite, carbon black),polymers (e.g., plastics, gels), carbon steel, ceramic, sand, carbon,silica, alumina, boron, or be any other suitable material. The supportmaterial 16 can be deposited as part of a support material carrier(e.g., paste), as powder, or in any other suitable form factor. Thesupport material 16 can be used to support working material overhangs,form negatives for the working material (e.g., wherein the workingmaterial can fill in the negative, be heated to conform to the negativegeometry, etc.), or be otherwise used. Alternatively, the viscosity ofthe working material carrier can be leveraged to create overhangs (e.g.,of less than 40°, 35°, 70°, etc.).

The deposition mechanism 200 of the system 100 functions to deposit apredetermined volume of material in a predetermined location within theworking volume. The material can include: the working material, thesupport material 16, metal, coatings, deposition reagents, treatmentreagents, or be any other suitable material. The system 100 can includeone or more deposition mechanisms. In a first variation, the system 100includes a different deposition mechanism for each material type. In asecond variation, the system 100 includes multiple deposition mechanismsfor one material type (e.g., an array of deposition mechanisms, an arrayof deposition heads connected to a common material reservoir, etc.). Ina third variation, the system 100 includes one deposition mechanism formultiple material types (e.g., both the working material and the supportmaterial 16 are deposited through the same head). When the system 100includes multiple deposition mechanisms, the multiple depositionmechanisms can be statically connected, translate independently,statically connected along a first axis and independently actuatablealong a second axis, or otherwise connected.

The deposition mechanism 200 can include a deposition head, materialstorage, and a deposition force mechanism. The deposition head 210 caninclude an extruder head, a print head, a needle, a spray nozzle (e.g.,inkjet, electrostatic, etc.), or include any other suitable head. Theextrusion aperture of the deposition head 210 can be symmetric (e.g.,circular, ovular, etc.), asymmetric, or have any other suitable shape.In a specific example, the deposition head 210 includes a needle with anextrusion aperture having a diameter between 50-500 μm, but canalternatively have extrusion apertures with diameters between 5-250 μmor 0.5-5 mm, or any other suitable diameter. The deposition head 210 canbe heated (e.g., to a material carrier melting point), unheated (e.g.,not actively controlled, equilibrated to room temperature, etc.),cooled, or otherwise thermally managed. Each deposition mechanism caninclude one or more deposition heads of same or different type.

The material storage 18 can include: a material reservoir retaining avolume of the material (e.g., a canister) or material reagent, a reel orspool of the material, a cartridge or set thereof (e.g., with differentmaterial carrier components), or include any other suitable storagemechanism. The material storage can be made of glass, ceramic, metal,plastic, or any other suitable material. Each deposition mechanism caninclude one or more material storage components of same or differenttype, wherein multiple material storage components can be fluidlyconnected or isolated. The material storage can be statically mounted tothe working volume 140 (e.g., top wall), translate with the depositionhead 210 (e.g., be mounted to the same translation mechanism as thedeposition mechanism); translate independently of the deposition head,or otherwise mounted. In one variation, the material storage 18 isconnected to the deposition head 210 by a fluid manifold (e.g., aflexible tube, rigid tube, etc.), but can alternatively be directlyfluidly connected to the head (example shown in FIG. 2 .; e.g., whereinthe head is mounted to a sidewall of the material storage; wherein thematerial storage and head are a unitary piece, etc.). However, thematerial storage can be otherwise connected to the deposition head.

The deposition force mechanism functions to move the material from thematerial storage to the deposition head. The deposition force mechanismcan be passive (e.g., driven by gravity, hydrostatic pressure, etc.),active (e.g., driven by a motor), or otherwise actuated. The depositionforce mechanism can be a set of rollers (e.g., coupled to the head andconfigured to pull material from a reel into the extrusion head), apiston (e.g., driven pneumatically, hydraulically, etc.), an auger, orbe any other suitable force-generation mechanism. The deposition forcemechanism can be connected to the material storage, wherein thedeposition force mechanism applies a deposition force (e.g., positiveforce) to the material within the material storage to force the materialtoward the deposition head. Alternatively, the deposition forcemechanism can be connected to the deposition head, wherein thedeposition force mechanism generates a suction force or feeding force topull material from the material storage into the head. However, thedeposition force mechanism can function in any other suitable manner.

The deposition mechanism 200 can optionally include a materialconditioning mechanism that functions to condition the material carrier12 before deposition (e.g., for deposition) and/or after deposition.Examples of conditioning the material carrier 12 includes: heating thematerial carrier 12 (e.g., melting, softening, etc.), reacting thematerial carrier 12 (e.g., with a light catalyst, etc.), mixing thematerial with a solvent, adding additives to the material, or otherwiseconditioning the material. The material conditioning mechanism can beintegrated into the deposition head, connected to the deposition head210 (e.g., precede the deposition head 210 along the print direction,follow the deposition head 210 along the print direction, etc.), to thematerial storage, to the manifold, to the working volume, to the stage,or to any other suitable component. For example, a deposition head canselectively heat the binder to the binder melting point prior to layerdeposition (when the material carrier 12 includes a binder). Examples ofthe material conditioning mechanism include: light emitting elements(e.g., lasers, UV light, IR light, etc.), heating elements (e.g.,resistive heating elements, corona discharge elements, etc.), coolingelements (e.g., fans, Peltier coolers, etc.), nozzles,pressure-generation elements, mixing elements, or any other suitablematerial conditioning mechanism.

The translation mechanism 300 functions to mount and translate thedeposition mechanism(s), or components thereof, within the workingvolume 140 along one or more axes. In one variation (example shown inFIG. 5 ), the translation mechanism 300 moves the deposition mechanism200 along the x- and z-axes, while the stage 500 controls y-axismovement. In a second variation, the translation mechanism 300 moves thedeposition mechanism 200 along the x- and y-axes, while the stage 500controls z-axis movement (e.g., along the print direction). In a thirdvariation (example shown in FIG. 6 ), the stage 500 is staticallymounted to the working volume, and the translation mechanism 300 movesthe deposition mechanisms and/or material manipulation mechanismsrelative to the stage 500 (e.g., along 3 axes, 5 axes, etc.). Thisvariant can be desirable when the workpieces are soft solids (e.g., havelow stiffness, low durometer, etc.) or have high brittleness, as stagemotion resulting in workpiece motion may deform the workpiece. However,the translation mechanism 300 can control movement along all axes,movement along a single axis, or control any other suitable translation.The translation system can include a tracking system (e.g., extendingalong the translation axis) and an actuator. The tracking system caninclude a rail system, set of tracks, a gantry system, or any othersuitable system capable of directing deposition mechanism translation.The actuator can include a rack and pinion assembly, a screw assembly, atoothed belt assembly, an electric motor, a stepper motor, anelectroactive polymer, or any other suitable actuator capable ofcontrolling deposition mechanism translation along the tracking system.The system 100 can include a different translation mechanism for eachaxis, or include a single translation mechanism that controlstranslation along multiple axes. For example, the system 100 can includea first translation system including an actuator coupled to an overheadrail extending along the x-axis, and a second translation systemincluding a second actuator coupled to each deposition mechanism thatcontrols z-axis translation.

The stage 500 (e.g., build plate) functions to retain the part precursor(e.g., workpiece) during material deposition, additive removal, and/orpart treatment. The layers are preferably deposited onto or over thestage, but can be otherwise deposited. The stage 500 is preferablyarranged within the working volume, opposing the deposition mechanism(s)(e.g., underneath the deposition mechanism), but can alternatively bearranged in any other suitable location and position. The stage 500 ispreferably removably mounted to the working volume 140 by clips, screws,tracks (e.g., a tongue-and-groove system), or any other suitablecoupling mechanism, but can alternatively be substantially permanentlymounted (e.g., built-in) to the working volume. The stage 500 can bemade of metal (e.g., ferrous, nonferrous), ceramic, plastic, or anyother suitable material. The stage 500 can additionally include heatingelements, cooling elements, function as a thermal distributionmechanism, or include any other suitable component. The stage 500 ispreferably planar, but can alternatively be curved (e.g., convex,concave, dimpled, etc.), or have any other suitable geometries orfeatures. The stage 500 is preferably level (e.g., substantiallyperpendicular to a gravity vector), but can alternatively be tilted(e.g., wherein the system 100 determines the tilt angle(s) andtransforms the printing coordinates to accommodate for the tilt) orotherwise oriented. In one variation of the latter variant, the layercan be deposited on a tilted stage, and be manipulated to be flat (e.g.,relative to the: prior layer, stage plane, a working volume coordinatesystem, etc.). However, the layer can be otherwise planarized. The stage500 can optionally include dampers (e.g., to absorb machining orprinting vibrations), levelers, or any other suitable mechanism.

The stage 500 can additionally translate the part precursor relative tothe deposition mechanism(s). The stage 500 can translate and/or rotatealong the x-axis, y-axis, z-axis, and/or any other suitable axis, or bestatic relative to the working volume. The stage 500 can be mounted toor include actuation mechanisms, such as gantries, linear motors, rotarymotors, or other actuation mechanisms that control the stage 500 motion.However, the stage 500 can actuate in any other suitable manner, andinclude any other suitable actuation mechanism.

The stage 500 position and/or workpiece position on the stage 500 can bemonitored and stored (e.g., registered) to track workpiece locationthrough one or more working volumes or through different manufacturingstages. The stage 500 position and/or workpiece position can be tracked:optically, using the stage 500 translation encoders, using probeoutputs, or otherwise tracked. Differences between actual and expectedpositions can be accommodated by: adjusting the working coordinates,adjusting the physical position of the stage 500 or workpiece, orotherwise accommodating the difference. The workpiece 20 canadditionally or alternatively be assigned an identifier, such that theworkpiece 20 can be identified and tracked through the differentmanufacturing stages. The workpiece identifier can be a stageidentifier, a workpiece surface pattern (e.g., pattern of scratches,etc.), an identifier printed or machined into the workpiece, or be anyother suitable identifier.

The system 100 can optionally include a workpiece retention mechanismthat functions to retain the workpiece 20 against the build plate and/orsupport the workpiece 20 during the material manipulation process, buildplate movement, and/or during any other suitable process. For example,the retention mechanism(s) can prevent the workpiece 20 from shearingoff the build plate while the workpiece 20 is being machined, whereinthe translational rupture strength (and/or retention force) generated bythe retention mechanism(s) matches or exceeds the machining strength,shear force generated by the machining tool, torsion generated by themachining tool, or other machining force applied to the workpiece. In afirst variation, the retention mechanism 510 can apply a substantiallyconstant force during the additive 14 manufacturing process. In a secondvariation, the retention mechanism 510 can be selectively operated toapply a retention force (e.g., attractive magnetic force) during certainprocesses (e.g., workpiece machining) and not others (e.g., materialdeposition). One or more retention mechanisms can be concurrently usedto retain the workpiece 20 (example shown in FIG. 7 ).

In a variation wherein the workpiece 20 (or portion thereof) is magnetic(e.g., ferrous, graphite-based, etc.), the stage 500 can be magnetic orinclude a magnetic mechanism 530 (e.g., permanent magnet, electromagnet)that generates a magnetic retention force 535 (e.g., magnetic attractionforce, repulsion force) that retains the workpiece 20 against the stage.The magnetic mechanism 530 can include: a permanent magnet array, anelectromagnet array, or any other suitable magnetic array including oneor more magnetic elements. The magnetic mechanism 530 can generate auniform magnetic force across the build plate, a variable magnetic forceacross the build plate, or generate any other suitable force. Themagnetic mechanism 530 can be arranged underneath the build plate (e.g.,generate an attractive magnetic force), above the build plate (e.g.,generate a repulsive magnetic force), to the side of the build plate(e.g., generate a magnetic force that resists a lateral manipulationforce), or otherwise arranged.

In a second variation, the retention mechanism 510 includes adhesive.The adhesive is preferably arranged in an interface layer 520 over thebuild plate surface proximal the deposition mechanism 200 and/ormaterial manipulation mechanism, but can be otherwise arranged. Theadhesive can include: graphite, boronitride, titania, silica, or anyother suitable adhesive. The interface layer 520 can additionally oralternatively include magnetic materials, reagents (e.g., that reactswith the material carrier), support material 16, or any other suitablematerial. However, the system 100 can include any other suitableretention mechanism.

In a third variation, the workpiece 20 can be retained on the stage 500by a raft of support material 16, wherein the support material 16 canadhere to the stage. However, the workpiece 20 can be retained againstthe stage 500 by Van der Waals forces, hydrogen bonds, electrostaticbonds, ionic bonds, covalent bonds, fixtures (e.g., clamps, softjaws,etc.), or any other suitable retention force or mechanism.

The system 100 preferably defines a working volume 140 (e.g., buildvolume) that the part is built within. The working volume 140 can bedefined by the volume accessible by the deposition mechanism 200relative to the stage, the volume defined by system supports or systemwalls, or otherwise defined. The system 100 can be a desktop unit with asmall footprint (e.g., 50 cm³ build volume), an industrial unit with alarge footprint, or be any suitable size.

The working volume 140 can be open to the ambient environment, partiallyenclosed, fully enclosed, connected to the ambient environment by amanifold (e.g., inlet manifold, vent manifold), or otherwise fluidlyconnected to the ambient environment. The working volume 140 preferablydefines a working volume lumen, which can be open, partially open, orentirely closed. The working volume 140 can be enclosed by a flexibleskirt, a housing (e.g., thermally conductive, thermally insulative), orotherwise enclosed.

Properties of the working volume lumen are preferably activelycontrolled (e.g., by an environment control mechanism, such as atemperature control mechanism), but can alternatively be passivelycontrolled, equilibrated with the ambient environment, or otherwisecontrolled. The environment control mechanism of the working volume 140can be the sintering mechanism's environment control mechanism, besimilar to one or more of the sintering mechanism's the environmentcontrol mechanism described below, or be any other suitableenvironmental control mechanism Properties that can be controlledinclude the working volume: temperature, pressure, composition (e.g.,nitrogen, oxygen, particulate, volatile or other composition'spercentage, ppm, or other measurement, etc.), or other property. Theproperty's average, mean, gradient, distribution, or other value for:the entire working volume, a localized print area (e.g., within athreshold distance of the workpiece, the layer, or other workpieceportion; a volume surrounding the workpiece 20 or region thereof), aregion adjacent the layer 10 (e.g., proximal a manipulated portion ofthe layer, a layer 10 region distal the manipulated portion of thelayer, an un-manipulated portion of the layer, etc.), or any workingvolume voxel or region can be monitored and/or controlled. The workingvolume 140 or portions thereof can be actively monitored (e.g., usingsensors 120 connected to or directed toward the working volume 140)and/or dynamically adjusted (e.g., by a control system 160 connected tothe sensors 120), passively monitored (e.g., inferred from tool signals,part deformation parameters, etc.), or otherwise monitored. Theproperties can be controlled during layer deposition, after the layer 10has dried or cured, during material manipulation, after materialmanipulation, after layer deposition until material manipulation (e.g.,including or excluding material manipulation), throughout the entireprocess, or controlled for any other suitable process or method stage.

In one variation, the system 100 can include a temperature controlmechanism that functions to control the localized or overall workingvolume temperature. The temperature control mechanism can be arrangedwithin the working volume, thermally connected to the working volumelumen, or otherwise arranged relative to the working volume. In a firstembodiment, the temperature control mechanism controls the workpiecetemperature. In the first embodiment, temperature control mechanismpreferably maintains the layers of the workpiece 20 at a substantiallyuniform working temperature (e.g., within 5 degrees C., within 0.5degrees C., within 0.005 degrees C. variance, less than a thresholdtemperature gradient, etc.) or within a working temperature range, butcan alternatively maintain portions of a single layer 10 at asubstantially uniform working temperature (e.g., wherein other layerscan have different temperatures) or working temperature range, maintainthe layers of the workpiece 20 at different temperatures, maintaindifferent sections of the workpiece 20 at different temperatures, orcreate any other suitable temperature distribution over the workpiece.The workpiece temperature can be maintained at a temperature that is thesame as, higher than, or less than the working volume temperature. In asecond embodiment, the temperature control mechanism maintains theentire working volume lumen at the substantially uniform workingtemperature (e.g., within 5 degrees C. variance), but can alternativelymaintain different portions of the working volume lumen at differenttemperatures. However, the temperature control mechanism can control thetemperature of any other suitable portion of the working volume.

The working temperature or working temperature range can be: less thanor within a temperature range of the material carrier depositiontemperature (e.g., within ±5° C., ±10° C., etc.); less than or within atemperature range of an uncooled manipulation tool operating temperature(e.g., the uncooled manipulation tool's temperature when manipulatingthe workpiece); at, above, below, or within a temperature range of thematerial carrier additive's phase transition point (e.g., evaporationpoint, normal boiling point, sublimation point, melting point, settingpoint, etc.); at or below a previous layer temperature; at or below:100° C., 65° C., or any other suitable temperature; between 45° C. to65° C.; between 30° C. to 40° C.; at, above, or below room temperature;and/or any other suitable temperature. Additionally or alternatively,the duration that the working volume region is held at a giventemperature and/or duration between successive manufacturing processes,such as the duration between successive layer deposition) can bedynamically adjusted to ensure that a threshold amount of the additiveis removed. In one example, the working volume 140 is held at theuncooled manipulation tool's operating temperature throughout theprocess, wherein the material carrier additive's boiling point is lowerthan said operating temperature. In a specific example, the additive'sboiling point is below 150° C., wherein maintaining the working volume140 at or around 100° C. evaporates the additive from the layer. Inanother example, the heat from the working volume and/or previous layerevaporates the additive from the deposited layer (e.g., wherein thedeposited layer's deposition temperature can be lower than, equal to, orhigher than the working temperature, such as room temperature). Inanother example, the working volume temperature is uncontrolled, whereinthe waste heat from the manipulation tool heats the working volume. Inanother example, the working volume temperature is held at, above, orbelow the material carrier's setting point or melting point.

The temperature control mechanism can include a heated stage, a heatingelement (e.g., heat lamp, resistive heaters, exothermic reactions, etc.)arranged above and directed toward the workpiece 20 or stage 500 (e.g.,mounted to the deposition mechanism 200 translation mechanism, aseparate translation mechanism, the working volume 140 interior, etc.),a lumen heating system (e.g., heaters arranged along the walls of theworking volume, a convection heating system, etc.), a cooling system(e.g., convection system, piezoelectric cooling system, fluid coolingsystem, etc.), the material manipulation mechanism 600 (e.g., throughwaste heat generated by material manipulation mechanism operation), acombination of the above, or any other suitable temperature controlsystem 160.

In a second variation, the system 100 can include a lumen qualitycontrol mechanism that functions to control the gaseous composition ofthe working volume lumen. In a first embodiment, the lumen qualitycontrol mechanism includes a vacuum shroud that removes gas,particulates, and/or material chips from the lumen. In one example, thevacuum shroud 620 can provide a negative pressure that is strong enoughto remove volatiles and particulates (e.g., smaller than a thresholdsize) from the lumen, but weak enough to leave chips (e.g., larger thana threshold size) from the lumen. The threshold size can be 1 micron, 10microns, 1 millimeter, 1 centimeter, or be any other suitable size.

The vacuum shroud 620 is preferably arranged proximal to, and is morepreferably aimed toward, the material manipulation mechanism, activeregion thereof, or manipulated layer, but can be otherwise oriented. Thevacuum shroud 620 can be concentrically arranged about (e.g., encircle)the material manipulation mechanism 600 (e.g., tool head), be offsetfrom the material manipulation mechanism 600 (e.g., next to the head,example shown in FIG. 4 ), or otherwise arranged. The vacuum shroud 620can have an annular geometry (example shown in FIG. 3A), segmentedannular geometry (example shown in FIG. 3B), be a tube, or have anyother suitable geometry. However, the vacuum can alternatively bearranged along a working volume wall (e.g., fluidly connected to thelumen) or otherwise arranged. The vacuum shroud 620 is preferablyfluidly connected to fluid manifold, wherein the fluid manifold can befluidly connected to the ambient environment, the lumen (e.g., whereinthe removed gas is recycled into the lumen), or to any other suitableendpoint. The fluid manifold can optionally include a filter, desiccant,catalyst, expansion chamber, magnetic particle collector, chip conveyersystem, selective membrane, condenser, or other regeneration mechanismthat preferentially removes particulates, volatiles, fluid, or othercontaminants from the vacuumed fluid. In a specific example, the systemcan include a magnetic element, generating an attractive and/orrepulsive magnetic force, that is arranged along the fluid manifoldupstream of a filter, wherein the magnetic element can extract ferrousparticulates (e.g., material particulates) from the fluid stream beforefluid filtration with the filter.

In a second embodiment, the lumen quality control mechanism can besimilar to the environment control mechanism of the sintering mechanism,and flood or selectively inject different gaseous compounds into theworking volume 140 to control the lumen atmosphere. In a thirdembodiment, the system 100 can include a pressure control mechanism thatcontrols the lumen pressure. The pressure control mechanism can includea pump, vacuum, or any other suitable fluid manipulation mechanism. In athird embodiment, the lumen quality control mechanism can be the chipclearing system. However, the system 100 can include any suitableenvironment control mechanism for the working volume.

The system 100 can optionally include an additive removal mechanism,which functions to remove additives from the deposited working material(e.g., paste). This can function to transform the part layer 10 orpartially-printed part into a green body (e.g., by removing the solvent)or a brown part (e.g., by removing the binder). The additive removalmechanism 400 is preferably controlled by the control system 160 (e.g.,that regulates power provided to the additive removal mechanism), butcan be otherwise controlled. The additive removal mechanism 400 can beoperable between a set of operation modes, each with its own set oftarget removal parameter values. For example, the additive removalmechanism 400 can be operated between a drying, curing, or hardeningmode (e.g., with a target temperature of 150-300 C) and a sintering mode(e.g., with a target temperature of less than 800 C, or 922 C to 1384 C,etc.), or any other suitable set of modes. The additive removalmechanism 400 can be arranged within the working volume, be external andselectively fluidly connectable to the working volume 140 (e.g., above,below, adjacent to, or entirely separate from the working volume), or beotherwise related to the working volume.

The additive removal mechanism 400 can be a thermal mechanism, anelectromagnetic mechanism (e.g., light system), a chemical reactionmechanism (e.g., wherein a gas or liquid reagent can be applied to thematerial layer 10 to bind, react with, or otherwise remove theadditive), vibration mechanism (e.g., to remove bubbles or particulateswith different sizes or densities), or any other suitable mechanism thatremoves the additive 14 in any other suitable manner. Example thermalmechanisms that can be used can include: a convection system including aheating element and a convection element (e.g., a fan, blower, etc.), aresistive heating system (e.g., a heated wire), an inductive heatingsystem (e.g., that applies electromagnetic eddy currents to the targetlayer 10 region), an electromagnetic heating system (e.g., microwaveheating system), IR system (e.g., a radiative heating lamp), waste heatfrom system components (e.g., the material manipulation mechanism, thecontrol system 160, etc.), heat from preceding print jobs (e.g., fromthe prior part's sintering process), or any other suitable thermalmechanism. In a specific example, a light mechanism is configured toheat the material layers to 150-350 C to remove solvents within thematerial carrier. The light mechanism can emit beam-shaped (e.g.,collimated) or diffuse light of one or more wavelengths (e.g., IR, UV,white light, etc.), and can include one or more light-emitting elements(e.g., LEDs, halogen lights, are lamps, tungsten lights, lasers, etc.),filters or coatings, lenses, or any other suitable light-parameteradjusting mechanism.

The system 100 can include one or more additive removal mechanisms ofthe same or different type. For example, the system 100 can include asingle solvent removal mechanism configured to remove solvent from themetal paste and the support material paste. The additive removalmechanism 400 can be statically mounted to the working volume, translatewith the deposition mechanism 200 (e.g., be mounted to the sametranslation mechanism as the deposition mechanism; example shown in FIG.2 ), translate independent from the deposition mechanism 200 (e.g., bemounted to a second, independent translation mechanism), or be mountedin any other suitable manner.

The system 100 can optionally include a material manipulation mechanismthat functions to shape one or more material layers. In particular, thematerial manipulation mechanism 600 can refine part geometries (e.g.,control part tolerances, define sharp features, shape interior corners,etc.), control layer 10 surface features (e.g., planarity, createinter-layer interface features), blend the interface between adjacentlayers, or otherwise shape the material layers. The materialmanipulation mechanism 600 preferably selectively manipulates a portionof the deposited layer(s), and can shape the layer sides, layer broadface (e.g., surface), layer 10 corners, or any other suitable layerportion. The material manipulation mechanism 600 is preferablycontrolled by the control system 160 (e.g., based on a virtual partmodel), but can be otherwise controlled. The system 100 can include oneor more material manipulation mechanisms of same or different type. Forexample, a first material manipulation mechanism can be used for theworking material, while a second, different material manipulationmechanism can be used for the support material 16.

The material manipulation mechanism 600 can be selectively selectedand/or controlled (e.g., by the control system 160) based on thematerial carrier 12 composition, the geometry to be formed (e.g.,tolerances, features), the layer 10 dimensions (e.g., thickness, width,length), layer temperature, layer rheology or deformability, or anyother suitable variable. For example, the head speed can be higher(e.g., between 50,000-100,000 rpm) when the material carrier 12 is abinderless paste, and be lower (e.g., less than 50,000 rpm) for a pastewith a polymeric binder. However, the material manipulation mechanism600 can be otherwise controlled.

The material manipulation mechanism 600 is preferably arranged withinthe working volume, but can alternatively be arranged outside of theworking volume, be separate from the working volume, or be otherwiserelated to the working volume. The material manipulation mechanism 600can be statically mounted to the working volume, translate with thedeposition mechanism 200 (e.g., be mounted to the same translationmechanism as the deposition mechanism), translate independent from thedeposition mechanism 200 (e.g., be mounted to a second, independenttranslation mechanism), or be mounted in any other suitable manner. Forexample, the material manipulation mechanism 600 can be mounted to thesame translation mechanism as the deposition mechanism, and can actuaterelative to the deposition mechanism 200 (e.g., translate along amachining axis, such as a z-axis) or be statically mounted relative tothe deposition mechanism 200 (example shown in FIG. 5 ; e.g., extendbeyond the deposition mechanism 200 along the deposition and/ormachining axis, be shorter than the deposition mechanism 200 along thedeposition and/or machining axis, etc.). The axial, rotational, angular,and/or other position of the material manipulation mechanism 600relative to the deposition mechanism 200 (e.g., deposition head) ispreferably known and accounted for through coordinate transformations orposition calibration (e.g., using a probe or reference point 601), butcan alternatively be unknown or otherwise managed.

The material manipulation mechanism 600 can include: material removalmechanisms (e.g., subtractive manufacturing mechanisms or heads),material deformation systems, lithography systems, or any other suitablesystem. Material removal mechanisms that can be used include: a cuttingtool, such as linear cutting tools (e.g., tool bits, broaches), orrotary cutting tools (e.g., drill bits, countersinks, counterbores,taps, dies, milling cutters, reamers, cold way blades; example shown inFIG. 2 ); mechanical abrasion systems; laser ablation systems;electromagnetic cutting systems; plasma cutting systems; fluid cuttingsystems (e.g., using directed pressurized fluid, such as air or liquid,with or without particulates, such as diamond); cavitation systems; gasgeneration systems; impact systems (e.g., chipping systems); or anyother suitable material removal mechanism. The cutting tool can beretained by a single-tool holder, a multi-tool holder (e.g., with a toolchanger, for soft tooling), or otherwise retained. Material deformationsystems that can be used include: flexible blades (e.g., paintingknives), directed pressurized fluid (e.g., gas, liquid, etc.), or anyother suitable material deformation system. The material manipulationmechanism 600 can double as the additive removal mechanism, wherein thematerial manipulation mechanism 600 can be operated in a first mode(e.g., low-power mode) to function as the additive removal mechanism,and operated in a second mode (e.g., a high power mode) to function asthe material manipulation mechanism. Alternatively, the materialmanipulation mechanism 600 can be separate from the additive removalmechanism 400. However, the system 100 can include any number of anyother suitable material manipulation mechanisms.

The material manipulation mechanism 600 can optionally include a chipclearing system that functions to remove material chips (e.g., materialremoved from the workpiece) from the workpiece 20 and/or stage. The chipclearing system can include: positive pressure systems configured todirect pressurized fluid (e.g., coolant, water, air) toward theworkpiece 20 (e.g., perpendicular the stage, parallel the stage, at anangle to the stage, etc.); negative pressure systems configured to suckchips away from the workpiece 20 (e.g., arranged proximal the materialremoval mechanism, arranged proximal the manipulated portion of theworkpiece, etc.); electromagnetic system (e.g., configured to generate amagnetic attractive force that attracts the chips); the lumen qualitycontrol mechanism; or include any other suitable chip clearing system.Alternatively, the material manipulation mechanism 600 can double as thechip clearing system, wherein the removed material can preferentiallyadhere to the material manipulation mechanism 6 oo instead of theworkpiece 20. However, the system 100 can include any other suitablechip clearing system.

The system 100 can optionally include a sintering mechanism thatfunctions to sinter the dried material layer. The material layer(s) canbe sintered between layer deposition processes, after the workpiece 20is completely printed (e.g., after an object precursor with geometryapproximating a virtual part model is formed), during layer deposition,during layer manipulation, or at any suitable time. In one variation,the additive removal mechanism 400 can double as the sinteringmechanism, such that the part is printed, optionally manipulated, andsintered in the same working volume (e.g., in-situ). In a secondvariation, the sintering mechanism 700 can be a different mechanism fromthe additive removal mechanism 400 (e.g., a separate and distinctvolume). The sintering mechanism 700 is preferably controlled by thecontrol system 160 based on the measured workpiece temperature, but canbe otherwise controlled. The system 100 can include one or moresintering mechanisms of same or different type (e.g., one for theworking material, one for the support material 16). The sinteringmechanisms can be statically mounted to the working volume, translatewith the deposition mechanism 200 (e.g., be mounted to the sametranslation mechanism as the deposition mechanism), translateindependent from the deposition mechanism 200 (e.g., be mounted to asecond, independent translation mechanism), or be mounted in any othersuitable manner.

The sintering mechanism 700 can be a thermal mechanism (similar ordifferent from the additive removal mechanism 400 thermal mechanisms), apressure-generation element (e.g., piston, pressurized chamber, etc.), alaser system, or any other suitable sintering mechanism. The thermalmechanism is preferably configured to heat the workpiece 20 or materiallayer 10 to 500-800° C., but can alternatively heat the workpiece 20 ormaterial layer 10 to 400-1000° C., or to any other suitable range. In afirst variation, the sintering mechanism 700 can be a set of heatingelements mounted to the working volume. In a second variation, thesintering mechanism 700 can be a heating chamber (e.g., furnace)adjacent and selectively fluidly connected to the working volume,wherein the stage 500 can be moved (e.g., automatically, using atranslation mechanism; manually, etc.) into the heating chamber. In athird variation, the sintering mechanism 700 can be a separate heatingchamber from the working volume, wherein the stage, supporting theworkpiece, is removed from the working volume 140 and inserted into theheating chamber (example shown in FIG. 9 ). However, the sinteringmechanism 700 can be otherwise configured.

The sintering mechanism 700 can optionally include an environmentcontrol mechanism that controls the sintering environment while thesintering region is being sintered (example shown in FIG. 2 ). Morepreferably, the environment control mechanism creates an inertatmosphere surrounding the sintering region. Alternatively, thesintering region can be sintered under atmosphere, in the presence of aweakly reducing species such as aliphatic alcohol vapor or carbonmonoxide gas, or in any other suitable atmosphere. In a first variation,the environment control mechanism includes an inert gas system,including an inert gas reservoir retaining the inert gas (e.g., mountedoutside the working volume, mounted within the working volume, etc.) anda fluid outlet (e.g., nozzle, etc.) fluidly connected to the sinteringregion. The inert gas system can optionally include a heating elementthat heats the gas (e.g., to a target temperature), a flow controlsystem 160 that controls gas flow through the system 100, or include anyother suitable component. The inert gas can include N2, He, Ar, Ne, Kr,Xe, Rn, CO2, or any other suitable compound. In a first embodiment, theenvironment control mechanism forms an inert gas curtain surrounding thesintering region. In this embodiment, the fluid outlet is preferablystatically coupled to and arranged around or adjacent the thermalmechanism, but can alternatively be separate from the thermal mechanismand independently controlled. This variant can optionally include aphysical, gas impermeable curtain or baffle that controls fluid flowtoward the sintering region. In a second embodiment, the environmentcontrol mechanism fills the working volume 140 with inert gas, whereinthe housing (defining the working volume) cooperatively forms theenvironment control mechanism. In a second variation, the environmentcontrol mechanism includes a suction mechanism that pulls a vacuumand/or removes air from the volume adjacent the sintering region.

The system 100 can optionally include a treatment mechanism 800 thatfunctions to treat the workpiece. Variants of the treatment mechanism800 include: an annealing mechanism, tempering mechanism, or agingmechanism including a heating chamber; a quenching mechanism including afluid cooling system (e.g., nozzle, reservoir, etc.) configured toimmerse or spray a gas or liquid coolant onto the workpiece; a hardeningmechanism including individually controlled heating elements and/orvolumes; an metal infiltrating system that infiltrates an infiltrantmetal into the printed matrix; a plating system; a passivating system; acarburizing system; a nitriding system; or include any other suitabletreatment mechanism. In one example, the annealing mechanism can heatthe workpiece 20 to a target temperature (e.g., 500-900° C.) over apredetermined heating duration (e.g., 30-300 minutes), hold theworkpiece 20 at the target temperature for a predetermined hold time(e.g., 10-60 minutes), and cool the workpiece 20 to a second targettemperature (e.g., ambient temperature) over a predetermined coolingduration. The additive removal mechanism 400 or sintering mechanism candouble as the treatment mechanism; alternatively, the treatmentmechanism 800 can be a separate component. The treatment mechanism 800is preferably controlled by the control system 160 based on the measuredworkpiece temperature, but can be otherwise controlled. The system 100can include one or more treatment mechanisms of same or different type.The treatment mechanism 800 is preferably arranged external the workingvolume 140 (e.g., above, below, adjacent to, or entirely separate fromthe working volume; examples shown in FIGS. 2 and 8 ), but canalternatively be arranged within the working volume, or be otherwiserelated to the working volume. The treatment mechanism 800 is preferablyfluidly connected to the working volume, but can be otherwise connected.

The treatment mechanism 800 preferably includes a thermal mechanism, butcan alternatively include a chemical treatment system or any othersuitable system. The thermal system is preferably a heating chamber(e.g., furnace) including a heating element, but can alternativelyinclude a directed heating system or any other suitable system. Theheating chamber can be a muffle furnace, box furnace, or any othersuitable heating chamber. The heating element 410 can include: aninductive heating element, resistive heating element, radiative lamp,combustion element, exothermic reaction, or any other suitable heatingelement.

The treatment mechanism 800 can optionally include an environmentcontrol mechanism, which can be the sintering mechanism's environmentcontrol mechanism, be the same mechanism as that of the sinteringmechanism, or be different from the sintering mechanism's environmentcontrol mechanism. The annealing mechanism environment control mechanismpreferably generates an inert or reducing atmosphere to preventoxidation of the metal part, but annealing can alternatively occur inambient atmosphere (e.g., when lower temperatures, such as 400-600 C isused), an oxidative atmosphere, or in any other suitable environment.Gasses that can be used to create the annealing atmosphere includeargon, nitrogen, hydrogen, water, ammonia, carbon monoxide, carbondioxide, boron-containing species, carbon-containing species, or anyother suitable compound.

The treatment mechanism 800 can optionally include a transportationmechanism that transports the workpiece 20 into the annealing mechanism(example shown in FIG. 2 ). In a first variation, the transportationmechanism is the stage, wherein the stage 500 is actuated (e.g., lifted,dragged, slid, dropped, etc.) into the annealing mechanism. In a secondvariation, the transportation mechanism includes a cart that retains thestage 500 and moves the workpiece 20 into the annealing mechanism (e.g.,through a controlled-environment passthrough, through ambientatmosphere, etc.). However, any other suitable transportation mechanismcan be used.

The system 100 can optionally include a set of sensors 120 that functionto monitor the working volume 140 during part manufacture (example shownin FIG. 2 ). The sensors 120 can provide the sampled signals to thecontrol system 160, wherein the control system 160 can control and/oradjust system component operation and/or working volume parameters:dynamically in real- or near-real time, after the build process, or atany suitable time. The system component operation and/or working volumeparameters can be controlled or adjusted using: equations, heuristics,probabilities, naïve Bayes methods, rules, decision trees, neuralnetworks, genetic programs, support vectors, or any other suitablemethod, wherein the method can be trained, generated, or otherwisegenerated manually, using supervised learning, unsupervised learning,regression, or any other suitable method.

Sensors 120 that can be used include: optical sensors (e.g.,multispectral cameras, hyperspectral cameras, visual range cameras,stereoscopic cameras, ambient light sensors, light emitting elements,LIDAR systems, laser projection systems, etc.), acoustic systems (e.g.,radar, microphone systems, ultrasound systems, etc.), temperaturesensors (e.g., thermocouple, IR analysis on an image of the workingvolume, etc.), pressure sensors, conductivity sensors (e.g.,conductivity probe), resistivity sensors, chemical sensors (e.g., oxygensensor), or any other suitable set of sensors. The system 100 caninclude one or more sensors 120 of the same or different type, mountedin an array or in different locations. The sensors 120 can be staticallymounted to the working volume, translate with the deposition mechanism200 (e.g., be mounted to the same translation mechanism as thedeposition mechanism), translate independent from the depositionmechanism 200 (e.g., be mounted to a second, independent translationmechanism), or be mounted in any other suitable manner. In one example,the system 100 can include an optical system mounted adjacent thedeposition mechanism, wherein the recorded images can be analyzed formaterial deposition rates, material deposition results (e.g.,imperfections, gaps, puddles, etc.), additive removal conditions (e.g.,temperature, drying uniformity across the layer, etc.), materialmanipulation results (e.g., gouges, imperfections, geometry variancesfrom tolerance thresholds, surface finishes, etc.), sinteringconditions, or any other suitable process parameter, wherein the sampledimages can be analyzed using image analysis techniques, such as objectrecognition techniques including HOG and SIFT, identification,detection, or any other suitable technique; motion analysis techniques,such as optical flow; or any other suitable image-based technique. In aspecific example, in response to determination that the layer 10geometries differ beyond a threshold difference form a target geometry,the system 100 can automatically control the material manipulationmechanism 600 to remove all or some (e.g., a localized region) of thelayer. In a second specific example, the system 100 automaticallyadjusts the extrusion parameters (e.g., temperature, extrusion rate,translation rate) based on the sensor feedback. However, the sensorfeedback can be otherwise used.

The system 100 can include a control system 160, which functions toperform the method disclosed below, and/or control operation of all or aportion of the system components (example shown in FIG. 2 ). The controlsystem 160 can be an on-board processor (e.g., microprocessor, CPU,GPU), remote computing system (e.g., server system connected through awired or wireless connection, such as cellular, WiFi, or othertechnology), connected user device (e.g., through a wired or wirelessconnection, such as BLE, NFC, or WiFi), be a combination of the above,or be any other suitable control system 160. The control system 160 ispreferably electrically connected to the system components, but can beotherwise connected to the components. The system 100 can include apower system, which functions to power the system components. The powersystem can be a battery system, power grid connector (e.g., plug), powerconversion system, chemical reaction, or be any other suitable powersystem. However, the system 100 can include a tool changer 603, toolcleaner 602 (e.g., for the manipulation head 610, deposition head 210),communication system, user interface, or any other suitable component.

4. Method

As shown in FIG. 10 , the method for additive metal manufacturingincludes: selectively depositing a material carrier within the workingvolume S100; removing an additive from the material carrier S200; andtreating the resultant material S300. The method can optionally includemanipulating the material S400; and monitoring the additivemanufacturing process and dynamically adjusting the additivemanufacturing parameters based on process monitoring S500. The method ispreferably performed by the system disclosed above, such as by thecontrol system of the system disclosed above, but can be performed by aremote computing system (e.g., remotely controlling the system), or byany other suitable system.

A variation of the method includes depositing a layer of metal pastewithin the working volume, removing solvent from the deposited layer(e.g., drying the layer), manipulating the dried layer (e.g., machiningthe dried layer), sintering the dried layer, repeating the method foreach successive layer of working material and/or support material untila workpiece with geometry approximating the virtual part model isformed, and sintering the workpiece. A second variation of the methodincludes: depositing layer of metal paste, manipulating the depositedlayer (e.g., manipulating the wet layer), drying the manipulated layer,repeating the above processes until a workpiece with geometryapproximating the virtual part model is formed, and sintering theworkpiece. However, the method can be otherwise performed.

The printed workpiece (e.g., pre-sintering, post-deposition,post-additive removal, post-machining, etc.) preferably has geometryapproximating the virtual model, and can have a near-net geometry orshape (e.g., within 10%, 5%, 3%, 1%, or less than 1% of the virtual partmodel geometry), be overprinted (e.g., have one or more dimensions thatare larger than 10% of the virtual part model dimensions), beunderprinted, or have any suitable geometry. In one variation, theprinted workpiece (or layer thereof) can have the near-net geometryafter layer deposition (e.g., for the entire part, a given slice),without layer manipulation. This variation can use a material carrierwith a low shrinkage percentage (e.g., less than 20%, 15%, etc.), suchas a binderless paste (e.g., that forms a high-density green body), orany other suitable material carrier. In a second variation, the printedworkpiece can have the near-net geometry after layer manipulation. Thisvariation can include overprinting the layer(s) (e.g., at a first, lowresolution), then machining the layer(s) to the near-net geometry (e.g.,at a second, higher resolution associated with the virtual parttolerance), or otherwise achieving the near-net geometrypost-manipulation. This variation can use a material carrier with a lowshrinkage percentage, a working temperature close to or encompassing theuncooled machining tool operation temperature (e.g., such that thelocalized layer regions do not breathe pre- or post-machining), or anyother suitable component or set of parameters. The printed workpiece(e.g., green body or brown body) preferably has a high density, such asover 60%, over 65%, over 75%, or over any suitable percentage density;however, the printed workpiece can have any suitable density.

The sintered workpiece preferably has a near-net geometry or geometrysubstantially matching the virtual part model (e.g., within thetolerances associated with the virtual part model), but canalternatively have any suitable geometry. The sintered workpiecepreferably has a high density (e.g., higher than 80%, 95%, 99%, etc.),but can have any suitable density.

Selectively depositing a material carrier within the working volume S100functions to selectively build the workpiece geometry, layer by layer.The resultant workpiece can be a green body, brown body, or have thedesired final composition. The resultant workpiece can have near-netgeometry or have any other suitable shape. The material carrier ispreferably deposited using the deposition mechanism described above, butcan alternatively be deposited using any other suitable system. Thematerial can be working material, support material, or any othersuitable material. The material carrier is preferably a paste includingthe material and a solvent, but can be any other suitable materialcarrier. Working material and support material can be concurrentlydeposited (e.g., concurrently operating different deposition mechanisms,which can be statically coupled together or actuate relative to eachother), sequentially deposited (e.g., depositing alternating layers ofworking material and support material), deposited in batches (e.g.,depositing a plurality of working material layers, then depositing aplurality of support material layers), or deposited in any othersuitable order. The material carrier is preferably deposited in apredetermined location within the working volume, but can be randomlydeposited (e.g., and subsequently selectively removed) or otherwisedeposited. The predetermined locations are preferably determined basedon a virtual part model (e.g., received from a user account, receivedfrom a computer aided design environment, etc.) using a virtual slicingmethod, but can be otherwise determined. The material carrier ispreferably deposited as a shaped layer (e.g., tracking the geometry ofthe virtual part slice), but can alternatively be deposited as asubstantially contiguous layer (e.g., wherein the part geometry issubsequently defined in the layer), or otherwise deposited. Thedimensions of the printed layer (e.g., width, thickness, length, etc.)can be determined based on the respective virtual model slice, theanticipated amount of shrinkage or deformation during subsequentprocessing processes (e.g., drying, sintering, annealing, machining,etc.), the resolution of the system, deposition mechanism, and/ormaterial manipulation mechanism, the tolerance associated with thevirtual part model, the printed geometry, or otherwise determined. Theprinted layer preferably has a resolution lower than the final partresolution, but can alternatively have the same or higher resolution.

In an embodiment including a hybrid manufacturing process, the layer canbe printed at a first resolution, then machined at a second resolutionhigher than the first resolution. The first resolution can be outside ofa resolution range associated with a virtual part tolerance (e.g.,tolerance associated with the virtual part), while the second resolutioncan be within said resolution range. The resolution range associatedwith the tolerance can be predetermined, empirically determined,calculated, selected, or otherwise determined. The resolution rangepreferably results in a final part (e.g., post-processing) havingphysical part dimensions within the virtual part tolerance (e.g.,wherein the resolution range accommodates for part shrinkage duringpost-processing), but can alternatively result in a workpiece (e.g.,green body, brown body) with dimensions within the virtual parttolerance, or be otherwise associated with the virtual part tolerance.However, the first and second resolutions can be otherwise related. Inone example, the width and/or length of each layer can be overprinted bya predetermined percentage (e.g., 3%, 10%, etc.), wherein subsequentmachining processes (e.g., milling) removes the excess material.However, the layer dimensions can be otherwise determined. The layer ispreferably deposited at a layer deposition temperature, which can be thetemperature of the material or material carrier measured upstream of thedeposition head, at the deposition head, at the deposited layer, betweenthe deposition head and the layer, or at any other suitable location.The deposited layer (e.g., printed layer, layer post-deposition)preferably has a printed layer temperature, which can be equal to,higher than, or equal to (e.g., after equilibration): the layerdeposition temperature, the workpiece's temperature (e.g., workpiecetemperature), the previous layer temperature (e.g., temperature of thelayer upon which the deposited layer was deposited), the working volumetemperature or ambient temperature, or any other suitable temperature.

Depositing material carrier S100 preferably includes: moving therespective deposition mechanism to the predetermined location within theworking volume with the translation mechanism, depositing the materialcarrier according to a predetermined set of deposition parameters, butcan be otherwise deposited. The deposition parameters can include:deposition speed (e.g., rate), deposition pressure, translation speed,layer thickness, layer width, layer length, layer spacing, materialcarrier temperature, material carrier viscosity, material carriercomposition, material carrier density, or include any other suitableparameter. The deposition parameters can be predetermined (e.g., basedon the virtual model, the material carrier composition, the material),dynamically adjusted (e.g., based on sensor feedback using a neuralnetwork, heuristics, or other determination method), or otherwisedetermined.

In one variation, depositing the material carrier includes flowing amaterial paste out of a nozzle into the working volume. In a secondvariation, depositing the material carrier includes heating a materialfilament (e.g., feedstock, metal admixed with thermoplastic, etc.) witha hot end (e.g., heated print head) to a softening temperature (e.g.,temperature just below the melting point of the material filament) priorto softened filament extrusion from the hot end and deposition into theworking volume. In this variation, the deposited layer can harden at theworking temperature, harden under subsequent heating (e.g., applied bythe additive removal mechanism), remain soft under the workingtemperature (e.g., to promote inter-layer adhesion), or have any othersuitable characteristic under the working temperature of the workingvolume.

Removing an additive from the material carrier S200 functions to dry,sinter, or otherwise process the material carrier. The resultantworkpiece can be a green body, brown body, or have the desired finalcomposition. The resultant workpiece can have near-net geometry or haveany other suitable shape. The removed additive is preferably solvent,but can alternatively be binder, gaseous bubbles, crystallinedeformations, dislocations, or any other suitable compound or inclusion.The additive is preferably removed with the additive removal mechanism,but can be removed by any other suitable component. The additive ispreferably removed within the working volume, but the workpiece can betransported to a second volume for additive removal and optionallyreturned to the working volume for subsequent material additionprocesses. The additive is preferably removed after layer deposition andbefore material manipulation (shown in FIGS. 11 and 12 ), but canalternatively be removed before or during layer deposition; before,during, or after material deposition; during or after materialmanipulation; or be removed at any other suitable time. The additive canbe removed on a layer-by-layer basis; concurrently removed from multiplelayers of working material, multiple layers of support material, ormixed layers of support and working material; concurrently removed froma workpiece with near net geometry; or removed at any other suitabletime. The additive can be removed from the entirety of a material layer,from a subset of the material layer, or removed from any other suitablematerial layer portion. In one example, a first portion of the layer isdried (e.g., additive removed) as a subsequent portion of the layer isbeing deposited, wherein the additive removal mechanism followsdeposition mechanism translation. In a second example, the layer isdried after the entire layer is deposited. In a third example, theambient volume proximal the predetermined location is maintained withina working temperature range, wherein the working temperature rangeencompasses or is higher than the phase transition point (e.g., normalboiling point) of the additive. The additive is preferably removedaccording to a set of removal parameter values (e.g., removal duration,temperature, pressure, location, power supplied to additive removalmechanism, cycling schedules, etc.) that can be predetermined (e.g., forthe entire part, for the material, for the specific layer, etc.),dynamically determined (e.g., based on results from the preceding layer,from adjacent layer regions, from instantaneous workpiece parameters,etc.), or otherwise determined. In a specific example, the removalparameter values can be set on a layer-by-layer basis, such thatdifferent layers in the resultant part can have different materialproperties.

Removing the additive S200 can include: controlling the temperature ofthe deposited material carrier, holding the deposited material carrierwithin a target temperature range, adjusting (e.g., dynamically,according to a predetermined schedule, cycling, etc.) the depositedmaterial carrier temperature, heating (and optionally holding) thedeposited material carrier within a target temperature range, applying areagent to the deposited material carrier, catalyzing a reaction in thedeposited material carrier, or otherwise removing the additive. Thedeposited material carrier is preferably held at a target temperaturerange equal to or lower than a reference temperature, but canalternatively be held at a temperature higher than, equal to, and/orotherwise related to the reference temperature. Alternatively, thedeposited material carrier can be heated to a temperature range abovethe reference temperature, or otherwise thermally manipulated. Thereference temperature can be the layer deposition temperature, theworkpiece temperature, the previous layer temperature, the substratetemperature (e.g., wherein the substrate can be the build plate, theprevious layer, or the workpiece that the new layer is deposited upon),working volume temperature, local volume temperature (e.g., of thevolume that the deposited layer will occupy, the volume adjacent thedeposited layer's volume, etc.), or any other suitable temperature. Thetemperature of the deposited material carrier can be locally controlledor globally controlled. For example, the method can control thetemperature of the working volume proximal or adjacent the depositedlayer, the temperature of the entire working volume, or the temperatureof the layer itself. The temperature of the deposited material carriercan be controlled for the newest deposited layer, for all depositedlayers, for specific layers (e.g., layers formed from a given material,layers with a large influence on the resultant part geometry, etc.), orfor any suitable set of layers.

The working volume is preferably held at the working temperature (e.g.,target temperature), but the working temperature can additionally oralternatively be set for the deposited layer, the layer being deposited,a working volume voxel proximal and/or within the layer volume (e.g.,volume that the deposited layer will occupy), the previous layer (e.g.,that the layer is being deposited upon), one or more workpiece layers,or any other suitable volume within the working volume. The workingtemperature is preferably equal to or less than a reference temperature,but can alternatively be higher than or otherwise related to thereference temperature (e.g., the same or different reference temperatureas that for the deposited material carrier).

The deposited material carrier parameters (e.g., temperature, pressure,etc.) can be actively or passively controlled. The parameters can becontrolled by controlling parameters of the paste (e.g., duringdeposition, after deposition), the working volume, a localized volume(e.g., proximal the layer(s)), a layer volume (e.g., volume that thelayer occupies or will be occupying), or any other suitable volume. Inone variation, controlling the parameters includes maintaining thetemperature of volume next to (e.g., adjacent, contiguous, overlapping)the prior layer (e.g., or support material, print material, or any othersuitable material), at or below a reference temperature during apredetermined time frame. The volume can be the working volumesurrounding the layer, the volume between the deposited layer and theprint heat, the next layer volume, or any other suitable volume. In asecond variation, controlling the parameters includes maintaining thetemperature of the layer itself at or below a reference temperatureduring a predetermined time frame. In a third variation, controlling theparameters includes maintaining the temperature of the previous layer ator below a reference temperature during a predetermined time frame. In afourth variation, controlling the parameters includes maintaining thetemperature of the volume proximal the next layer at or below areference temperature during a predetermined time frame. However, theparameters can be otherwise controlled. The reference temperature can bethe working volume temperature, previous layer temperature, layerdeposition temperature, or be any other suitable temperature. The timeframe can be: throughout a method process (e.g., throughout deposition,throughout manipulation, etc.), within a method process (e.g., during aportion of deposition or manipulation), between method processes (e.g.,after deposition until manipulation, etc.), or be any suitable time.

In a first variation, holding the deposited material carrier within thetemperature range can include maintaining and/or selectively heating orcooling all or a portion of the working volume to the workingtemperature range with waste heat from the machining head, an activetemperature control system (e.g., a set of actively controlled heatingelements), or a combination thereof. In one example, the working volumevoxel(s) proximal the printed layer can be maintained (held) at theworking temperature (example shown in FIG. 14 ) throughout thedeposition process of one or more subsequent layers. In a secondexample, the deposited material is not heated by a localized heatingelement (e.g., hot air, laser) within the working volume betweendeposition and machining and/or next layer deposition. In a secondvariation, holding the deposited material carrier within the temperaturerange can include maintaining the temperature of a volume (e.g., of theworking volume, of the volume the layer is being deposited into, of thelayer being deposited, of the deposited layer, etc.) adjacent theprevious layer at or below the reference temperature (e.g., layerdeposition temperature, previous layer temperature, etc.): afterdeposition until selective machining; throughout subsequent layerdeposition; or for any suitable time period. In one example, thisincludes heating the deposited material carrier or layer with a heatlamp remote from the deposited material layer to maintain the ambientworking temperature within the working temperature range. In a thirdvariation, heating the deposited material carrier includes moving aninductive element or resistive heating element proximal the layer andoperating said element in an additive removal mode. In a fourthvariation, heating the deposited material carrier includes directing alocalized heating element (e.g., laser, hot gas) at the layer andoperating the localized heating element in an additive removal mode.However, the additive can be otherwise removed.

The method can optionally include manipulating the material S400, whichfunctions to refine the geometry of the printed material. Examples ofgeometry refinement can include: removing the material to achieve adesired geometry, finishing a material surface (e.g., side, top),patterning a material surface (e.g., to achieve a desired pattern, toincrease the inter-layer binding area, etc.), or otherwise refining thegeometry of the material surface. The manipulated layer and/or resultantworkpiece preferably has a near-net geometry, but can alternatively havea larger geometry or any other suitable geometry.

Material manipulation S400 can additionally or alternatively change thematerial properties of the printed material (e.g., work harden thematerial). The material is preferably manipulated within the workingvolume but can alternatively be manipulated in a separate volume (e.g.,wherein the workpiece is transferred to the separate volume formanipulation). The material is preferably manipulated by the materialmanipulation mechanism, but can alternatively be otherwise manipulated.The manipulated material can be the working material, the supportmaterial, or be any other suitable material. Material manipulation canbe applied globally (e.g., to the entire layer or piece), locally (e.g.,to a sub-region of the layer), or to any other suitable workpieceregion.

The material is preferably manipulated after material deposition, morepreferably after layer deposition and/or solvent removal (example shownin FIGS. 11 and 15 ), but can alternatively be manipulated: during layerdeposition (e.g., a first portion of the layer manipulated as a secondportion is being deposited); before additive removal (e.g., drying;solvent removal) as shown in FIGS. 12 and 16 , sintering, or materialtreatment; after additive removal; after a rough part has been printed(e.g., sprayed into a mold); or at any other suitable time. The materialis preferably manipulated on a layer-by-layer basis (e.g., manipulatedafter each layer is deposited, sintered, or treated), but can includeconcurrently manipulating multiple layers (e.g., the method includesprinting multiple layers, then manipulating the plurality of layers),manipulating the near-net geometry workpiece (e.g., the workpiece itselfcan be machined), or manipulating the part precursor at any othersuitable time.

All or portion of each layer (e.g., interior sides, exterior sides,broad face, etc.) can be manipulated. In one variation, the method caninclude printing a plurality of support layers, machining the pluralityof support layers to define a negative of the desired geometry, andprinting working material into the negative. In a second variation, themethod can include printing a working material layer, machining theinterior sides of the layer to a predetermined geometry and/or finish,repeating the process until all layers are printed, and finishing theworkpiece exterior with a secondary machining process. However, materialmanipulation can be otherwise used.

The manipulated portion of each layer is preferably determined based onthe virtual part slice, but can alternatively be determined based onsensed layer parameters of the deposited layer (e.g., using an opticalsystem), or otherwise determined. In one variation, the method includes:determining (e.g., estimating) a layer volume within the working volumebased on the virtual part slice, and determining the location andposition of the layer portion (to be manipulated) based on the portionsof the layer volume extending beyond the virtual part slice. Themanipulated portion location can be relative to the layer position,relative to a working volume reference point (e.g., using the workingvolume coordinates), based on translation mechanism odometry, orotherwise determined. In a second variation, the method includes:determining the layer parameters of the deposited layer (e.g., layerdimensions, layer position, layer volume, layer configuration, etc.),comparing the deposited layer to the reference virtual part slice (or aderivative virtual part slice that accommodates for part dimensionalchange throughout the process), and determining the deposited layerportions extending beyond the reference virtual slice as the manipulatedportion(s). The layer parameters can be determined using computer visiontechniques, odometry techniques (e.g., wherein the layer dimensions aredetermined from the translation mechanism's prior locations),weight-sensor based techniques (e.g., wherein the layer parameters aredetermined from the amount and position of the workpiece weight changeas measured at the stage), feed rate techniques, or otherwisedetermined.

Variants of manipulating the material include: machining the materialwith a cutting tool, such as a mill; spreading the material; ablatingthe material, such as with a laser (e.g., the same or different from theadditive removal mechanism); grinding the material with a grinder,polishing the material; electric discharge machining the material;milling the material; etching the material; sputtering the material;coating the material; or otherwise manipulating the material. In aspecific example, the method includes machining excess material from thedeposited, dried material layer to meet a predetermined geometry,determined from the virtual part model. In a second specific example,the method includes directing one or more lasers at excess material,wherein the lasers heat the binder to generate a gaseous product thatablates or cavitates to remove excess material. Different manipulationmethods can be used for different material types (e.g., a first methodfor the working material, a second method for the support material),different material layers (e.g., a first method for intervening layers,a second method for the top layer), different layer regions (e.g., afirst method for layer sides, a second method for the layer broad face),or other workpiece portions; however, the same manipulation method canbe used.

Manipulating the material S400 can optionally include cooling a cooledregion proximal the manipulation head. Alternatively, the localizedregion cannot be cooled (e.g., remain uncooled). The cooled region canbe the manipulated portion of the layer, proximal portions of theworkpiece, the manipulation head 610, a localized portion of the workingvolume proximal the manipulated layer portion or manipulation head, orbe any other suitable region. The cooled region can be cooled before,during, or after manipulation. The cooled region can be cooled by:spraying coolant toward the cooled region; removing hot gas from thecooled region (e.g., using a vacuum); moving cooler fluid toward thecooled region (e.g., blowing cooler gas toward the region, liquidcooling the manipulation head, such as through a channel within thehead); or otherwise cooling the cooled region.

The method can optionally include treating the material S300, whichfunctions to adjust the material properties of the material. Treatingthe material can include: sintering, annealing, aging, quenching,tempering, selectively heat treating (e.g., using differentialhardening, flame hardening, induction hardening, case hardening, etc.),cryogenic treating, decarburizing, sputtering, coating, work hardening,passivating, or otherwise treating the resultant material. The materialtreatment is preferably performed by the treatment mechanism (e.g.,annealing mechanism, etc.) according to a set of treatment parametervalues, but can be performed by the additive removal mechanism, thesintering mechanism, or by any other suitable mechanism. The treatmentparameter values can be determined based on the desired part properties,be manually determined by a user, be determined based on the workingmaterial, or be otherwise determined. The material treatment ispreferably performed in a treatment volume separate from the workingvolume, wherein the workpiece is transferred (e.g., lifted, dropped,slid, etc.) into the treatment volume, but can alternatively beperformed within the working volume. The material treatment ispreferably applied after the piece is completely printed (e.g., appliedto the final workpiece with near-net geometry), but can alternatively beapplied before, during, or after each layer or plurality thereof hasbeen deposited, dried, or manipulated, be treated after the part issintered, or at any other suitable time.

Treating the material can include sintering the material, whichfunctions to further compact the material and/or prevent workpiecedeformation from subsequent dimensional changes. Sintering the materialcan optionally release the workpiece from the stage (e.g., bydeactivating or burning off the workpiece-stage interface layer), removesupport material (e.g., de-bind the support material, decompose thesupport material, etc.), or perform any other suitable function. Thematerial is preferably sintered by the additive removal mechanism, butcan alternatively be sintered by a dedicated sintering mechanism or byany other suitable mechanism. The material is preferably sintered withinthe working volume (e.g., in-situ) but can alternatively be sintered ina separate volume. In the latter variant, the workpiece, stage andworkpiece, or other set of components can be removed from the workingvolume and inserted into the separate volume. One or more layers of sameor different material can be concurrently sintered. For example, eachlayer can be sintered after the layer is deposited and dried (e.g.,additive removed). In a second example, multiple layers can be sinteredtogether. All or a portion of a layer can be sintered. For example, afirst layer region can be sintered while a second layer region remainsunsintered.

Sintering the material preferably includes heating the material (e.g.,with a heat lamp, with unfocused light, etc.) according to a set ofsintering parameters (e.g., temperature, duration, cycling patterns),but the material can be otherwise sintered. Sintering the material canadditionally include: creating a controlled environment surrounding asintering region of the workpiece; and sintering the material within thecontrolled environment (e.g., operating the additive removal mechanismin a sintering mode). In a first variation, creating the controlledenvironment includes filling a sealed working volume with inert gas(example shown in FIG. 8 ). This can be performed before the material isdeposited (e.g., wherein the entire process is performed in a controlledenvironment), after material deposition (e.g., wherein part of theprocess, such as sintering, is performed in the controlled environment),or at any other suitable time. In a second variation, creating thecontrolled environment includes creating a localized controlledenvironment by flowing inert gas through a nozzle directed at thesintering region (example shown in FIG. 2 ). The inert gas is preferablyheavier than air, but can alternatively be lighter than air. Sinteringthe material can optionally include moving the sintering mechanism 700to the sintering region (e.g., with the translation mechanism). In onevariation, the first portion of the layer is sintered as a subsequentportion of the layer is dried or deposited. In a second variation, alayer is sintered after the layer is deposited and dried. However, thematerial can be sintered at any other suitable time.

The method can additionally include monitoring the manufacturing processusing a set of sensors S500 and adjusting subsequent manufacture basedon the sensor outputs. The sensors can include any combination of thosedescribed above, or include any other suitable set of sensors. Examplesof manufacturing process parameters that can be monitored include: layersurface finish, layer deformities, layer temperature, materialtemperature, material feed rate, material manipulation properties (e.g.,chip shape, chip color, etc.), or any other suitable parameter. In afirst example, this can include: recording images of the workpiecewithin the working volume and analyzing the images to extractmanufacturing characterizations (e.g., using image segmentation, objectrecognition, topology analysis, motion detection, video tracking,optical flow, pose estimation, object classification, etc.). In responseto layer defect detection (e.g., incorrect geometry, gouges, scratches,material carrier anisotropy, etc.), the method can include: removing andreprinting the entire layer (e.g., with the material manipulationmechanism); removing and reprinting a layer portion contiguous with thedefect; or otherwise fixing the defect. The response to layer defectdetection can be predetermined, dynamically determined (e.g., based onan optimization function, heuristics, historical data, etc.), orotherwise determined. In a second example, the method can includedetecting a deposition mechanism slow-flow state (e.g., from the images,from a flow sensor on the deposition head, etc.) and automatically:notifying a user (e.g., at a user device, by playing a sound, etc.),initiating a cleaning process (e.g., dipping the deposition head in acleaning solvent, purging a set amount of material, cycling throughdifferent temperatures, etc.), or otherwise reacting to the slow-flowstate. In a third example, the method can include determining adifference between an actual and expected workpiece position within theworking volume (e.g., based on image analysis, probe readouts, etc.),and automatically adjusting the printing instructions (e.g., theprinting coordinates) to accommodate for the positional shift. In afourth example, the sensor measurements recorded during manufacture canbe used to determine operation parameters for manufacture of subsequentrelated parts. For example, the sensor measurements, coupled withquality control classifications, can be used to train a neural networkthat automatically determines the manufacturing parameter values forsubsequent part manufacture. However, the feedback can be otherwiseused.

The method can optionally include receiving a virtual part model S600,wherein the virtual part model specifies the desired geometry of thefinal part (example shown in FIG. 13 ). The virtual part model can bereceived from a user, a remote computing system (e.g., server), or fromany suitable source. One or more virtual part models can be received atone or more times from the same or different sources, and can bemanufactured in parallel (e.g., in the same working volume, in differentworking volumes, etc.), serially, in the same run, or in any suitableorder. The virtual part model preferably specifies the part geometry,and can optionally specify the desired tolerance range, materials, orany other suitable information. The method can optionally includetransforming the virtual part model to accommodate for anticipateddimensional changes during physical part manufacture (e.g., increasingthe virtual part model dimensions along one or more axes). Thetransformation can be determined: manually, empirically, heuristically,iteratively, using a neural network, probabilistically, or otherwisedetermined.

Embodiments of the system and/or method can include every combinationand permutation of the various system components and the various methodprocesses, wherein the method processes can be performed in any suitableorder, sequentially or concurrently.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. An additive manufacturing system, comprising: a buildvolume; a material deposition head arranged within the build volume; asubtractive machining head arranged within the build volume; a buildplate arranged within the build volume underneath the subtractivemachining head, wherein the build plate comprises an interfacialmaterial selected to retain a build material during build materialmanipulation, the interfacial material arranged on a surface of thebuild plate proximal the subtractive machining head; and a controlsystem electrically connected to the material deposition head and thesubtractive machining head; and a heating chamber configured to: receivea part precursor, wherein the part precursor is coupled to the buildplate by the interfacial material; and sinter the part precursor to forma physical object; wherein the material deposition head is configured todeposit the build material and a support material on the build plate;and wherein the subtractive machining head is configured to machine thebuild material; and wherein the interfacial material degrades duringsintering, releasing the part precursor from the build plate.
 2. Thesystem of claim 1, wherein the interfacial material comprises anadhesive.
 3. The system of claim 2, wherein the adhesive comprises atleast one of graphite, boron nitride, titania, or silica.
 4. The systemof claim 1, wherein the interfacial material, cooperatively with thebuild material, generates a layer attachment force that exceeds a shearforce exerted on the build material during build material manipulationwith the subtractive machining head.
 5. The system of claim 1, whereinthe material deposition head is configured to deposit the interfacialmaterial onto the build plate.
 6. The system of claim 1, wherein thesubtractive machining head is configured to machine the interfacialmaterial.
 7. The system of claim 1, wherein the build plate comprises acarbonaceous material.
 8. The system of claim 1, wherein the buildmaterial comprises less than 8% binder by weight.
 9. The system of claim8, wherein the build material comprises: metal scaffold particles havinga D50 particle size; and metal infiltrant particles with a D50 particlesize less than 25% of the D50 particle size of the metal scaffoldparticles.
 10. The system of claim 9, wherein the metal infiltrantparticles primarily position in interstitial spaces between the metalscaffold particles.
 11. The system of claim 9, wherein the D50 particlesize of the metal scaffold particles is between 10 μm and 20 μm, andwherein the D50 particle size of the metal infiltrant particles isbetween 2 μm and 10 μm.
 12. The system of claim 1, wherein the buildmaterial comprises a solvent.